VERFAHREN ZUR GEWINNUNG VON ANORGANIKA AUS DEINKINGSCHLAMM

摘要

A process for recovering inorganic material from a deinking sludge obtained as reject material in the recovery of recycled fiber from waste paper. In accordance with the invention the process comprises the following steps: (a) the proportion of organic material in the form of fiber material in the deinking sludge is 15-40% (dry solids content), (b) the water content of the sludge is adjusted so that the dry solids content becomes 10-35%, step (a) and step (b) being so adapted to each other that the sludge is pumpable, (c) the pressure of the sludge is increased to at least 22 MPa, (d) the temperature is increased to supercritical or near supercritical temperature, (e) a medium containing oxygen is added to the sludge to oxidize all organic material at supercritical temperature and pressure in a reactor, (f) energy released at the oxidation of the organic material is recovered, and (g) the flow of material from which energy has been recovered and which comprises said inorganic material, gases and water, is subjected to material separation for recovery of the inorganic material.